In conventional road finishers with floating screeds, the screed, which is articulated to the chassis of the road carrier and is drawn thereby, is held in a desired position or moved, so that defined laying conditions are met, by means of hydraulic actuating cylinders which are connected on the piston side or housing side to the chassis of the road finisher and on the piston-rod side to the screed.
In the laying of mixed material, allowance must be made for various factors which decisively influence the laying quality. For example, the temperature of the mixed material to be laid has an important role. It is also important to adhere to a constant laying speed. External disturbances may mean that the position of the screed has to be rapidly altered in relation to the substrate. During stopping or starting of the road finisher, particular skill is required in order to properly carry out the construction work and thus to avoid expensive reworking